Drums conventionally employ a cylindrical drum body defining a hollow chamber, and a drum skin, on one, or both ends of the body. The drum skins are mounted in hoops which supports the skins. Tensioning devices are attached to the exterior of the body, and to the hoops. By adjusting the tensioning devices, the drum skins can be made tighter or looser.
Usually there are drum skins and hoops and tensioning devices at both ends of the body.
All of this has been well known. Drums will have different sounds depending on the depth of the drum body. A drummer may require a drum with a body of one size for one type of performance and may require a drum with a body of a different size for another performance. This would require an investment in two or more drums of different sizes. The drummer will have the inconvenience of carrying several drums of different sizes, if they are required for an occasion.
Various proposals have been made to provide a drum with an extension for the body. The intent has been that the drummer can modify the drum by increasing or decreasing the depth of the drum body.
However, the proposals that have been made in the past have been somewhat cumbersome and complex. The construction of a drum requires tensioning devices, located at spaced points around the circumference of the drum skin(s), These devices must be attached to the drum body, so that the skin(s) can be tensioned equally around the drum body. Where there are both top and bottom drum skins, it may be desirable to tension one skin at a tension different from the other. For this reason separate top and bottom tension devices are provided.
These features are provided with conventional drums, by attaching the tensioning devices to the drum body. The tensioning devices connect to each drum skin ring by means of tension rods, in this type of drum. It is found that the tension rods should be kept out of contact with the drum body, since any contact may impair the sound of the drum.
Where it has been proposed in the past to attempt to provide a drum with a drum body which can be extended, these features have been a compromise. Clearly it would be necessary to attach and secure the various parts of the drum body together. However, the components for such attachment should be free of contact with the drum body as far as possible, for the reasons explained above.